Atomically acquire a weak reference to the shared object referred to by this representation. The behavior is undefined unless 0 < numWeakReferences() || 0 < numReferences().
0 < numWeakReferences() || 0 < numReferences()
Declared in <bslma_sharedptrrep.h>
<bslma_sharedptrrep.h>
void acquireWeakRef();